The invention relates to improvements in methods of and apparatus or systems for pneumatically transporting successive commodities of a series of commodities in a conduit wherein the commodities are propelled by a flow or stream of a gaseous fluid, e.g., compressed air.
Systems of the above outlined character are utilized for the transport of numerous commodities, for example, to advance plain or filter cigarettes, filter rod sections and/or other rod-shaped articles or products of the tobacco processing industry into or from storage facilities and/or between different levels, as well as to change the orientation (such as the direction of advancement) of successive products (e.g., through angles close to or matching 90xc2x0).
In order to ensure predictable and efficient advancement of certain commodities by resorting to a pneumatic transporting system, especially the transport of products into and from mass-producing machines or production lines, it is necessary to design the path for the advancement of successive commodities (normally within a pneumatic conduit) in such a way that the commodities are compelled to advance in the conduit with minimal or negligible play, i.e., that a small or very small quantity of the selected gaseous fluid can flow around and forwardly beyond the conveyed commodities. In other words, the efficiency of a conventional transporting system for discrete commodities depends, to a large extent, upon the configuration and upon the dimensions of the path which is established for pneumatic propulsion of discrete commodities from a first station (sender) to a second station (receiver).
Numerous problems arise when a pneumatic transporting system is selected for the advancement of elongated rod-shaped commodities such as plain or filter cigarettes, rod-shaped sections of filters for tobacco smoke and/or other rod-shaped products of the tobacco processing industry. For example, if a cigarette or another non-elastic rod-shaped commodity is to be transported within a conduit along a path which is configurated to change the orientation of the cigarette (e.g., through a right angle or thereabout), it is necessary to increase the inner diameter of a certain length of the conduit in order to ensure that the cigarette can change the direction of its advancement (e.g., from horizontally to vertically or vice versa) without undergoing any (or any appreciable) permanent deformation.
The just discussed problems can be overcome, at least to a certain extent, if there is ample room to accommodate a conduit having one or more arcuate sections with large radii of curvature. However, such room is not always available (or is not available at all) in numerous plants (such as in cigarette making factories) which are designed for mass production of rod-shaped articles and wherein hundreds of discrete machines or production lines are normally installed in a single room in close or immediate proximity to each other.
In accordance with heretofore known proposals, the above outlined problems are sought to be overcome by employing pneumatic conduits which include arcuate sections having large or huge inner diameters so that a cigarette or an analogous essentially non-elastic commodity can change the direction of its advancement without undergoing any (or any appreciable) permanent deformation. Reference may be had, for example, to published German patent application Ser. No. 21 65 782. However, and as already pointed out hereinbefore, the efficiency of such pneumatic transporting systems is low (and often too low) because a high percentage of gaseous fluid (such as compressed air) is free to bypass a cigarette advancing in a large-diameter arcuate section of the conduit. The situation is aggravated if the cigarettes are to be advanced from a lower level to a higher level, i.e., when the gaseous conveying fluid is compelled to overcome the action of gravity force upon the advancing commodities. For example, the just outlined situation can develop when filter rod sections (e.g., filter mouthpieces of double or six times unit length) are to be transported from a filter rod making machine (e.g., a machine of the type disclosed in U.S. Pat. No. 3,974,007 granted Aug. 10, 1976 to Greve for xe2x80x9cMETHOD AND APPARATUS FOR THE PRODUCTION OF FILTER ROD SECTIONS OR THE LIKExe2x80x9d) to a tipping machine (e.g., a machine of the type described and illustrated in commonly owned U.S. Pat. No. 5,135,008 granted Aug. 4, 1992 to Oesterling et al. for xe2x80x9cMETHOD OF AND APPARATUS FOR MAKING FILTER CIGARETTESxe2x80x9d).
An object of the present invention is to provide a pneumatic transporting system which overcomes the aforediscussed drawbacks of conventional systems in a simple, efficient and space-saving manner.
Another object of the invention is to provide a pneumatic transporting system which can be utilized with particular advantage in tobacco processing plants for controlled and predictable conveying of huge quantities of rod-shaped articles (such as plain or filter cigarettes, cigars or cigarillos and/or filter rod sections) between different levels and/or through great distances at a high frequency such as is required in a modern tobacco processing plant.
A further object of the invention is to provide a novel and improved method of transporting huge quantities of cigarettes, filter rod sections and/or other non-elastic rod-shaped commodities through short and/or great distances as well as between different levels (if and when necessary) without affecting the integrity, the appearance and/or other desirable characteristics of the conveyed commodities.
An additional object of the invention is to provide a cigarette making machine or production line which embodies one or more transporting systems exhibiting the above outlined characteristics.
Still another object of the invention is to provide the improved apparatus with a novel and improved combination of a conduit and one or more gas flow admitting and regulating units.
A further object of the instant invention is to provide an economical pneumatic transporting apparatus which can be put to use as a superior substitute for heretofore known apparatus for the transport of rod-shaped commodities of the tobacco processing industry.
One feature of the present invention resides in the provision of a transporting system for a series of commodities, e.g., rod-shaped commodities such as filter mouthpieces of multiple unit length. The improved apparatus comprises a pneumatic conduit which defines a predetermined path for successive commodities of the series and for a first stream or flow of a gaseous fluid (such as compressed air) serving to propel the commodities along the path in a predetermined direction, and means for admitting into the path an additional flow of gaseous fluid which assists the first flow in propelling commodities in the predetermined direction.
The conduit is or can be provided with discrete first and second inlets which respectively serve to admit the first flow and the additional flow into the predetermined path. At least one of the flows can contain compressed air, i.e., a compressed gaseous fluid.
The conduit can include an arcuate section which is located downstream of the second inlet (as considered in the predetermined direction). That portion of the path which is defined by the arcuate section of the conduit can have a cross-sectional area larger than that of the conduit section(s) located upstream and/or downstream of the arcuate section. For example, the arcuate section of the path can be designed (curved) in such a way that it can change the direction of transport of successive commodities through an angle which matches or approximates a right angle.
The second inlet can be defined by an adjustable valve, e.g., by a signal-responsive open-and-shut valve which is set up to intermittently admit the gaseous fluid of the additional flow into the elongated path by way of the second inlet. Such system can further include regulating means for opening the valve in response to propulsion (by the first flow) of a commodity past the second inlet. The regulating means can include at least one sensor which serves to monitor the path for the presence of commodities in the region of the second inlet. The sensor is arranged to generate signals which serve to effect an opening of the valve in response to advancement of commodities beyond the second inlet.
If the commodities are rod-shaped articles, the path can include a portion having a circular cross-sectional outline, located at the second inlet and having a diameter which at least approximates the diameter of a rod-shaped article.
Another feature of the present invention resides in the provision of a method of transporting a series of commodities, e.g., rod-shaped articles of the tobacco processing industry. The improved method comprises the steps of establishing an elongated path for the advancement of successive commodities of the series, pneumatically propelling successive commodities in a predetermined direction along the path by resorting to a first flow (stream) of a gaseous fluid, and introducing into the path a second flow of a gaseous fluid to thus enhance the propelling action of the first flow.
The gaseous fluid of at least one of the flows can be constituted by compressed air.
The propelling step includes or can include advancing successive commodities of the series at spaced-apart intervals, and such method can further comprise the steps of monitoring a predetermined portion of the path and generating signals upon detection of commodities in the predetermined portion of the path. The introducing step of such method can include admitting into the path gaseous fluid in response to the signals and behind the respective commodities (as seen in the predetermined direction).
If the commodities are elongated rod-shaped articles (such as plain or filter cigarettes or filter rod sections) , the propelling step includes advancing the articles lengthwise.
If the path exhibits an arcuate section upstream of a first at least substantially straight section and downstream of a second at least substantially straight section (as seen in the predetermined direction), the introducing step can include admitting into the second at least substantially straight section of the path a stream of compressed gaseous fluid behind each of successive commodities of the series to thus promote the advancement of commodities into and along the arcuate section of the path.
If the commodities are elongated rod-shaped articles, the establishing step can include imparting to the path a configuration such that a rod-shaped commodity advancing along the path changes its direction of movement through a predetermined angle, e.g., an angle which is at least close to 90xc2x0.
Furthermore, the establishing step can include providing a path wherein the commodities advance from a first level to a second level, e.g., from a lower level to a higher level. Such advancement can take place while the commodities change the direction of their advancement (e.g., through 90xc2x0 from a movement in a horizontal plane to a movement in a vertical plane).
Still further, the establishing step can include providing a path (e.g., a substantially L-shaped path) having at least one section wherein the commodities are propelled with a negligible play.
The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved apparatus itself, however, both as to its construction and the modes of assembling, installing and operating the same, together with numerous additional important and advantageous features and attributes thereof, will be best understood upon perusal of the following detailed description of certain presently preferred specific embodiments with reference to the accompanying drawing.